Gas actuated power device



P 1963 L.-H. GARLINGHOUSE 3,104,125

GAS ACTUATED POWER DEVICE Filed March 28, 1960 2 Sheets-Sheet 1 ESL/EHGQRL/NGHOUSE 84 L INVENTOR.

Q M 82 Zw /X AT TORN 5Y5 P 1963 L. H. GARLINGHOUSE 3,104,125

GAS ACTUATED POWER DEVICE Filed March 28, 1960 2 Sheets-Sheet 2 LESLJEEGmzu/veyo USE [NIT/V701? ATTORN EYS United States Patent 3,104,125 GASACTUATED PUWER DEVKZE Leslie H. Garlinghouse, Pasadena, Calif, assignorto Garlinghouse Brothers, Los Angeles, Calif a copartnership Fiied Mar.28, 1960, Ser. No. 17,880 Claims. ((1294-69) The invention relates topower actuated devices and has special reference to heavy duty devicessuch as power hooks, concrete placing buckets and the like which arelifted about construction jobs by cranes and other comparabletransporting machinery from place to place where they need to beoperated. Hooks, for example, need to be hooked and unhooked for placingheavy loads; concrete buckets need to be opened for dumping the heavyload of mixed concrete either in small quantities or the entire contentsof the bucket all at one time and subsequently also need to be closedfor reloading and also closed from a partly opened position if thecontents are not entirely disposed of.

Heretofore compressed air has been depended upon for operations of thiskind connected to the apparatus by means of a long high-pressure airline which can be readily hooked and unhooked to the air system on thebucket or similar device when ready for operation. The devices of theprior art, although effective where air is available, have limitationsin that if the travel of the device exceeds the length of the air lineeither additional length of an air line must be interposed or the sourceof compressed air may have to be moved. Air lines of excessive lengthlose a considerable amount of pressure and have the further drawback ofnecessitating an unwieldy length of hose. On the other hand, compressingequipment, even though portable, cannot always be placed where neededclose to the operation, and hence there are limitations where suchequipment is used.

It is therefore among the objects of the invention to provide a new andimproved portable power actuated device which is equipped with tankscapable of being filled with a compressed gas so that the power unit isself-contained and can be transported entirely free of any source ofcompressed air or other gas, necessitating only the manipulation of thesuitable valve at the spot when the device is to be operated.

Another object of the invention is to provide a new and improvedself-contained high-pressure gas operating mechanism which has aconsiderable capacity and consequently can be operated for long shiftswithout the necessity of renewal of the gas supply.

Still another object of the invention is to provide a new and improvedportable self-contained gas actuated mechanism which is capable of usinggases which can be liquefied at normal temperatures, but underconsiderable pressure, the device being so arranged that the pressurecan be effectively reduced to a moderate operating pressure thereby tomake use of relatively inexpensive piping and equipment which would notbe possible if the full pressure of the liquefied gas were turned intothe system.

Still further among the objects of the invention is to provide a new andimproved portable gas pressure actuated device which is dependable underconditions of extremely great demand and where heavy loads are to behandled without a prospect of frosting or freezing as the high-pressuregas leaves the cylinders in which it is stored upon the device.

With these and other objects in view, the invention consists in theconstruction, arrangement and combination of the various parts of thedevice, whereby the objects contemplated are attained, as hereinafterset Patented Sept. .17, 1963 forth, pointed out in the appended claimsand illustrated in the accompanying drawings.

In the drawings: a

FIG. 1 is a longitudinal sectional view of a concrete placing bucketchosen by way of example to which the gas pressure actuated system isattached in a portable fashion.

FIG. 2 is a fragmentary longitudinal view taken on the line 22 of FIG.1.

FIG. 3 is a schematic view showing the various parts of the systeminterconnected in the same manner as shown in FIG. 1.

FIG. 4 is a side-e-levational view of a power hook with portions thereofbroken away showing engagement of the hook with the bail of a bucket.

FIG. 5 is a fragmentary sectional view taken on the line 5-5 of FIG. 4.

FIG. 6 is a schematic view showing the hook in open position.

FIG. 7 is a schematic view similar to FIG. 6 showing the hook in closedposition.

FIG. 8 is a schematic illustration of the gas circuit connected to theoperating cylinder.

FIG. 9 is a fragmentary schematic representation of the gas circuitapplied to the operating cylinder of the bucket of FIG. 1.

Although only two forms of the invention, namely, a power hook and aconcrete placing bucket, have been shown by way of example, it is to beunderstood that this is exemplary only of typical devices which can beoperated by the system and that the system contemplates installation onother comparable devices and sundry material handling mechanisms whichcan be operated by movement of a lever.

In an embodiment of the invention chosen for the purpose of illustrationthere is shown a frame 10 which in this instance is a concrete placingbucket provided with a sling or bad 11 to which a lifting device may beattached by means of a cable (not shown) to some stationary support forlifting the frame about from place to place as for example from one partof a stationary sup port to another. The frame is provided with a lowerrim 13 upon which it can rest and an upper reinforcing ring 14 to whichthe brackets are secured. A hopper 15 is located within the frame andextends downwardly so that the outlet end 16 lies immediately above therim 13. Gates 17 swung on arms 18 pivoted on shafts 19 swing in oppositedirections to open and close the outlet end. A spring 20 normally holdsthe gates in closed position. Arcuate racks 21 mesh with each other sothat when an actuator lever 22 secured to one only of the arms 18 ismanipulated, both gates open and close at the same time.

Portions of the frame structure contribute appreciably in the operatingrelationship of the bucket and its mechanism. It will be noted that theframe 10 extends entirely around the hopper 15 at a distance spacedsufficiently from the inwardly tapering walls of the bucket to entirelyencase the mechanism. The lower rim 13 extends a distance somewhat lowerthan all of the interior parts and protrudes outwardly therefrom toserve the purpose of not only a bumper when the bucket is hauled aboutbut also as a stand when the 'bucket is lowered to some surface.Stiffening angles 23 may the used about the hopper. Intermediatechannels 25 surrounding an intermediate area of the hopper serve as ameans for anchoring plates 26 above which the arms 18 are pivoted. Thestructure on opposite sides is substantially identical and hence oneside only is shown in the drawings.

The inwardly sloping character of the hopper leaves an ample space 27which entirely surrounds the lower end of the hopper inwardly withrespect to the frame 10.

For manipulating the gates, there is provided a pneumatic ram orcylinder 30. The cylinder is secured at its upper end to a plate 31 withthe assistance of a bracket 32 which forms part of the head of thecylinder. The cylinder is provided with a piston 33 shown schematicallyin FIG. 3 to which is attached a piston rod 34 extending through asuitable packing 35 downwardly toward the lever 22 to which it ispivotally attached by means of a link 36. Clearly, therefore, as thepiston is reciprocated the piston rod and lever 22 will pull the gatesto open position when the piston moves upwardly as viewed in FIGS. 1 and3 and will move the gates to closed position when the piston movesdownwardly.

Power for actuating the pneumatic ram or cylinder is supplied from tanks40, 41 and 42. The tanks are designed to contain gas under pressure andin quantity sufficient to operate the device for considerable periods oftime. The pressure present in the tanks is many times greater than theoperating pressures of the pneumatic cylinder, but by reason ofemployment of the circuit shown and described, the high-pressure presentin the cylinder is reduced to an operating pressure before traveling tothe ram, and because of this system exceedingly high tank pressures canbe employed thereby to make possible the storage of operating gas insubstantial quantities. It will further be understood that devices ofthe type herein described as, for example, the concrete placing bucketare relatively rugged pieces of equipment.

The lifts which make use of handling devices of this kind are capable ofheavy loads. Also the structure of the device as previously noted isspecially adapted to protection of the parts when banged about in themidst of concrete forms, scaffolding and structures already present inthe vicinity. Hence, the equipment is capable of having installedtherein tanks of considerable cubic capacity at the protected locationsand aggregating in number sufiicient to have available large volumes ofthe chosen actuating fluid.

Various different types of fiuids which act as gases under ordinaryoperating pressures may be employed although some have been found moreadvantageous than others. A fluid found particularly advantageous iscarbon dioxide which can be stored in the tanks either in liquid orsolid form depending upon the pressures employed. The carbon dioxide gasis relatively inexpensive and has the further advantage of beingharmless when exhausted into the atmosphere in the vicinity of theoperation.

Other gases which in practice have been found utilizable include theliquid petroleum gases such as butane, propane and glotane. The physicalproperties of the gases mentioned permit them to he used advantageouslyin that substantial quantities can be stored in the spaces available inthe tanks and the cost is not excessive. Such gases, however, are usedpreferably in open spaces where discharge periodically of smallquantities from the apparatus will not create a hazardous conditionbecause of their combustible nature.

Inorganic gases of certain kinds are also usable as, for example,nitrogen where especially high pressures can be accommodated in thetanks, and where the cost consideration is less critical. Carbon dioxidegas will be referred to primarily in the description inasmuch as itoffers an extremely desirable operating gas the action of which isreadily explainable. Accordingly, it may be assumed that the tanks 40,41 and 42 have been charged with liquefied or solidified carbon dioxidegas under pressures in the neighborhood of 1500 lbs. per square inchinitially. It should be understood in suggesting an initial chargingpressure that the pressure will depend to some degree on the particulartanks chosen, the size of the tanks and the charging equipmentavailable. Practical operating pressures may range all the way from 700lbs. per square inch to 1500 lbs. per square inch or slightly higher orlower depending upon local conditions. The tanks when l full ofliquefied gas may weigh from 50-150 lbs. each and even though ofappreciable weight can readily be accommodated by the equipment hereinshown and described.

Where buckets of large capacity are equipped with the gas pressuresystem, three tanks may be needed as illustrated in the drawings, but itwill be understood that for lighter equipment two or perhaps only onetank may sufiice. Since the tanks must be periodically removed whenempty and replaced with charged tanks, a releasable mounting isdesirable. In the chosen embodiment there is provided a cradle 43 at thebase of each tank, the cradle being fastened to the rim 13 by suitableconventional fastening means.

A band 44 secured to appropriate channels 25 serves to clamp the tank ineach instance properly, the band being supplied with a suitableconventional fastener 45 which can readily be released and securedwhenever a tank needs replacement.

When a multiple number of tanks are employed, they are manifoldedtogether by employment of a manifold 46 to which gas lines 47, 48 and 49are connected, the gas lines feeding respectively from the tanks 40, 4-1and 42. In order that any one or all of the tanks may be removed at onetime, each tank is provided with a shut-off valve 50 at the tank whichcommunicates through a short line 51 with a coupling element 52 in turnconnected to a coupling element 53 in the respective gas line. A valve54 in the gas line is provided in order that a communication between themanifold and the respective tank can be shut off at any time especiallywhen the coupling elements 52, 53 are to be separated. The main gashigh-pressure supply line 56 connected to a main gas low-pressure supplyline 56 leads from the manifold 46 to the cylinder 30. In the main gassupply line 56 is a pressure reducing valve 57 of sufiicient capacity toreduce the aggregate of pressure from the tanks to the working pressurefor the cylinder 30. The system performs efiectively when the workingpressure on the downstream side of the pressure reducing valve is about100 lbs. per square inch. It should further be noted that where amultiple number of tanks are manifolded together to supply a single maingas supply line at a pressure substantially less than the pressurepresent in the manifold, the manifold should be of substantial capacitymaterially greater than the capacity of the low-pressure gas supply line56'.

In some instances a pressure relief valve 58 may be provided for thehigh pressure supply line 56 in order to prevent accumulation ofpressure in the line 56 above a certain optimum amount. Since the tanks40, 41, 42 are usually fused, a relief valve can be dispensed with inthe manifold 46.

In the low-pressure main gas supply line 56' is an operating valve 59which is adapted to be manipulated by pull ropes 60 and 61 in order toturn the operating valve either to open position, closed position orexhaust position. The pull ropes can extend outwardly or downwardly fromthe device in any desired manner so as to be within reach of an operatorpositioned in the vicinity of the device when operation is desired.

The low-pressure main gas supply line 56' connects through a fitting 62to a feed line 63 and thence through a fitting 64 to a line 65 supplyingthe cylinder 39. It will be noted that the lower end of the cylinderreceiving as it does gas under pressure directly from the source ofsupply may be considered as the high-pressure end of the cylinder.

Also extending from the fitting 64 is a reservoir supply line 67 whichconnects directly to a reservoir 68. A check valve 69 in the reservoirsupply line is set in a direction such that once gas has been passed tothe reservoir, it cannot back-flow through the reservoir supply line 67.Inasmuch as the pressure on the downstream side of the reducing valve 57is set at some low point such as about 100 lbs. per sq. in, this willbecome the pressure in the reservoir as well as the pressure at thehigh-pressure end of the cylinder. For purposes of description thecylinder may be said to be divided by the piston into a high-pressurechamber 71 and a lowpressure chamber 72.. A filter 73 protects thecylinder and the reservoir and appropriate portions of the system fromharmful foreign particles which might otherwise be carried into theoperating portion of the system.

From the reservoir 68 a supply line 74 extends into communication with alow-pressure supply line 75 which connects to the low-pressure chamberof the cylinder 30. Between the supply line 75 and the low-pressuresupply line 74 is a series of valves comprising a pressure regulatingvalve 76, check valve 77 and a relief valve 78. A gauge 79 may also beemployed on the downstream side of the pressure regulating valve todenote the pressure coming from the pressure regulating valve whichultimately :finds its way into the low-pressure chamber 72 of thecylinder.

Under circumstances where pressure in the reservoir is at about C) lbs.per square inch, effective operating performance can be enjoyed when thepressure regulating valve 76 reduces pressure to the low-pressurechamber of the cylinder to about lbs. per square inch. The effect ofthis relationship in operation is that when the gates are to be opened,a gas under pressure is introduced into the high-pressure chamber 7 1 ofthe cylinder. This is gas which has been once reduced in pressure fromtwk pressure to operating pressure. When operation is initiated, it maybe assumed that there is a negligible pressure in the low-pressurechamber 72 and that air present in the cylinder at that time will becompressed as the piston 33 moves upwardly and will be forced outwardlyinto atmosphere through the relief valve 7 8 should the pressure exceed20 lbs. per square inch in the particularly chosen example. At the sametime gas under pressure is being supplied to the highpressure chamber71, the gas is also being supplied to the reservoir 68 at the samepressure. When this has occurred for long enough to build up gaspressure in the reservoir 68 to about 100 lbs. per square inch, thesecond step in the cycle of operation is ready.

Where it is assumed that the first step opens the gates 17, the secondstep will be to close the gates 17. To accomplish this, the operatingvalve 59 is set to exhaust position in which pressure in the line 65 andin the lowpressure main gas supply line 56' is reduced to atmosphericpressure. This condition will also prevail in the reservoir supply line67 as far as the check valve 69. At this stage of operation gas at 20-lbs. gage pressure passing from the reservoir 68 through the regulatingvalve 76 supplies the low-pressure chamber 72 with gas at 2.0 lbs. persquare inch gage pressure sullicient to overcome the atmosphericpressure in the high-pressure supply chamber 71 and force the piston 33.and piston rod 34 downwardly which motion acting through the lever 22closes the gates 17.

Thereafter, when opening operation is again desired, the operating valve59 is turned to open position to permit gas to flow at 100 lbs/ sq. in.in the direction and through the system as previously described. Whenthis gas pressure reaches the high-pressure chamber 71 and beginspressing against the piston 33, there will be 20 lbs. pressure in thelow-pressure chamber 72 acting against the piston. There remains,however, a pressure diff r ntial f 80 ibs/ sq. in. which is sufficientto move the piston upwardly and which is the force which performs theWork of opening the gates 17 When it becomes necessary to stop the gatesat any selected partially open position, the operating valve 59 is setto an adjustment Where exhaust is shut off and no gas flows. At thispoint pressures on opposite sides of the piston will temporarilyequalize and the gates will remain in the selected position. positionthe gates can be moved in either direction either to further openposition or to closed position.

Should an occasion arise where it might become desirable to use anoutside gas supply as, for example, to conserve the pressure .in thetanks, or in the event that tanks might not be available, additionalconnections and fittings can be employed. Under such circumstances itmay be assumed that there is available a compressor 3i) which suppliesgas under pressure through a compressor line 81 to an operating valve82. An outside pressure line 83 communicates between the operating valve82 and a quick-connect coupling 84. The quick-connect coupling may be aconventional Westinghouse air brake connection or other appropriateconventional connection which can be quickly made and broken and whichonce made is capable of holding pressures at least as high as theselected opera-ting pressure of 100 lbs/sq. in. or something higher.

From the coupling 84 is an intake line 85 which connects with thefitting 62. A shut-oil valve 86 is provided in the line 85 and anothershut-off valve 87 is provided in the low-pressure main gas supply line56. Hence, when operation as a result of gas pressure from the tanks isto be discontinued for any reason, the shut-off valve 87 is closed andthe shut-off valve 86 may then be opened. Thereafter, whenever thedevice is to be op erated, a connection is made through the coupling 84thereby to interconnect the compressor 80 with the system.

From the foregoing description it will be understood that the system isan extremely versatile one being capable of a change over from a supplyof gas self-contained in the unit to an outside source of gas underpressure and vice versa merely by manipulating two shut-01f valves and aquick-disconnect coupling 84. Although some modifications in the tankequipment might become desirable for accommodating gases of differentkinds, the principle of operation remains the same and is one capable ofmaking use of gases and almost any practical working level above 100pounds in the tank portion of the device which is effectively reduced tooperating pressure for the ram or cylinder 30 whether that pressure be100 lbs. per square inch or considerably lower or higher than 100 lbs.per square inch. The relationship capable of moving the gates to openposition, closed position or intermediate position remains.

In a second form of the invention the self-contained gas power actuatorsystem is shown mounted for actuating a power hook. The hook isindicated generally by the reference character 90 where it is shown ascarried by means of a cable 91 attached to a bracket 92, the bracketbeing broken away to show the relative location of the mechanism butcomprising also a frame 93. In this embodimentlthe hook is shownattached to a bail 94 which forms a means of carrying an article 95which may be a bucket or any other load which needs to be transportedfrom place to place. The apparatus more particularly is one capable oflifting relatively heavy loads which may exceed many tons.

The hook portion of the apparatus, in fact, consists of two hook members96 and 97 which are pivotally mounted upon a shaft 93 carried by theframe 93 to which the shaft is secured by appropriate nuts 99. Bronzebushings 100, 100 may be employed to improve the ease of rotation of thehook members about the shaft. Spacers 101 and 1432 fill the remainder ofthe space between par-ts of the bracket 92. Stiifening bolts 103, 104and 105 assist in spacing opposite sides of the frame 93 and holding thesides in proper position with the help of a bolt 106 at the top of thebracket 92. An operating arm or extension 107 on the hook member 97cooperates From partially open I 7 with a similar operating arm orextension 108 on the hook member 96 for opening and closing the hook asshown in FIGS. 6 and 7.

To perform the work of opening and closing the hook, there are provideda series of gas containers 109, 110 and 111 in the chosen embodimentwhich is for heavyduty work. These containers may be filled with anappropriate gas under pressure such as liquefied CO or any of the gas%suggested in connection with the first described embodiment of theinvention. The containers are connected to a manifold 112 by means ofpipes 113, 114 and 115 in which are appropriate check valves 116. If theindividual valves are not used for relief, a relief valve 117 set at anappropriate pressure may be employed connected to a gas line 119 asshown.

Inasmuch as the container or tank pressure may be many hundreds ofpounds or perhaps more than a thousand pounds, it is necessary forpractical operation to reduce the pressure to a working pressure of, forexample, about 100 lbs. and this is accomplished by employment of areducing valve 118 in the gas line 119 leading from the manifold 112. Ashut-off valve 120 may be inserted in the line 119 so that the line maybe effectively turned off when not in operation. In the gas line 119downstream from the reducing valve is a filter 123 and a gas receivertank 124. Fnom the gas receiver tank a short line 125 connects with anautomatic operating valve here shown as a four-way valve 126 whichoperates a ram indicated generally by the reference character 127. Theram may be described as comprising a cylinder 128 within which a piston129 separates the cylinder into a forward acting or opening chamber 139and a rearward acting or closing chamber 131. One gas line 132 suppliesthe forward acting chamber and another gas line 133 supplies the reverseacting chamber. The four-way valve 126 may operate in any approvedconventional fashion such as when the valve is turned so as to supplygas under pressure to the line 132, the gas returning through the line133 will be vented through an exhaust Vent 134 and, conversely, when thevalve is passing gas to the line 133 gas under pressure from theopposite chamber through the line 132 will vent through the same vent134.

A rotating actuator 135 on the valve device may be connected to theconventional pneumatic valve interior operating means in such fashionthat when the actuator is rotated it shifts the valve alternately from aposition passing gas to the line 132 to a position passing gas to theline 133 and then again to line 132 as the actuator continues to berotated. In the chosen embodiment, rotation is continuously in aclockwise direction as viewed in FIGS. 4, 6 and 7. To accomplishrotation, a ratchet wheel 136 is mounted upon the actuator and thiswheel is moved by action of a dog 137 upon reciprocation of an operatorrod 138, the rod being reciprocatably mounted in a platform 139 on theframe which supports the fourway valve 126 and the gas receiver 124. Inthe operator rod is a link 140 acting through a spring 141 to place ayielding connection in the operator rod to assure smoothness ofoperation. A pawl 142 prevents reverse rotation of the ratchet wheel136.

To effect reciprocation of the actuator rod, there is provided a curvedplate 143 pivotally secured to a bracket 144 on the frames. A triggerplate 145 is connected to the plate 143 and overlies another plate 146which is jointed to the link 140 by means of a pin 147. The trigger liesat a location extending into a crotch 148 of the frame extending belowthe upper end of the crotch as shown particularly in FIGS. 4, 6 and 7.The trigger also lies substantially along the vertical center line ofthe hook midway between opposite hook members 96 and 97.

In operation when it is assumed that the hook members are closed andsupport the bail 94 as it then becomes desirable to release the bail byopening the hook members, the cable 91 is lowered until the article 95rests on some supporting surface after which the cable is lowered stillfurther a distance sutficient to have the hook members moved downwardlyuntil the bail 94 moves to the dotted position 94 of FIG. 4. When thisoccurs, the bail will move against the trigger 145 which, acting throughthe operator rod 138 rotates the ratchet wheel 136 a distance sufiicientto shift the four-way valve to the new setting. It may be assumed thatthis is a setting passing gas under pressure to the line 133 and theforward acting or opening chamber 131. In this adjustment the piston 129will move from left to right as viewed: in FIGS. 4, 6, 7 and 8, therebymoving a piston rod 149 from left to right as viewed in FIGS. 4, 6, 7and 8. The piston rod is attached to the operator extension 107 and,inasmuch as the cylinder 128 is attached through a collar 150 to theoperating extension 108, the hook members are moved from the closedposition of FIGS. 4 and 7 to the open position of FIG. 6 which also isshown by dotted lines in FIG. 4. The cable 91 can then be elevated andthe hook removed from the vicinity of the load.

When it again becomes desirable to close the book from the open positionof FIG. 6, the cable 91 is again lowered with the open hook membersspread on opposite sides of the bail 94. The cable is then lowered untilthe bail strikes the trigger 145 whereupon the operator rod 133 is againmoved upwardly advancing the ratchet wheel 136 one more notch to aposition wherein the adjustment of the four-way valve is changed. Thenew adjustment is one which passes gas under pressure to the line 132and the closing or reverse-acting chamber 130 while, at the same time,venting gas from the chamber 131 through the line 133 and thence throughthe valve to the vent 134. Acting in this fashion, the piston rod 149 ismoved from right to left as viewed in FIGS. 4, 6, 7 and 8. This has theeffect of causing the operating extensions 107 and 108 to be spreadapart and, at the same time, causing the hook members 96 and 97 to bemoved together to the relationship shown in FIG. 7, closed under thebail '94. Now when the cable 91 is elevated, lifting the hook, the hookelements will engage the bail and the article can be lifted to a newlocation. Ends 151 and 152 may be used for resting the book as a wholeupon some supporting surface when it is not in use in a fashion whichprevents interference with the operating mechanism.

On those occasions where it may become desirable to use the operativemechanism of FIG. 8 in connection with a bucket of the type illustratedin FIGS. 1, 2 and 3, the cylinder 30 may be attached to the four-wayvalve 126 in the manner shown in FIG. 9 by connecting the line 132 tothe chamber 72 and the line 133 to the chamber 71. The operator rod 138and trigger 145 may be mounted to operate in a manner similar to thatalready described by having the trigger located where it can engage someportion of a stationary object 153. This is sufficient to manipulate theoperator rod reciprocatably to shift the four-way valve 126 alternatelyfrom one position to the next. When gas is passed through the line 132to the chamber 72, venting at the same time chamber 71, the piston rod34 will move generally downwardly in a direction closing the gate 17. Onthe next alternate operation of the operator rod and four-way valve 126the gas passed through the line 133 to the chamber 71 will operate toelevate the piston rod 34 as the chamber 72 is vented, thereby to openthe gate 17.

From the foregoing description it will be clear that the device is onewhich is completely self-contained inasmuch as the containers 109, and111 can be suitably mounted upon the frame 93 where they can betransported with the frame and the rest of the mechanism. The samegeneral mounting scheme has already been described in connection withFIGS. 1, 2 and 3 and is appropriate to both types of devices. Similarly,the automatic opening and closing operation is equally adapted to bothtypes of devices on those occasions where it might, for some reason, bedesirable to move elements such as the gate 17 or the hook members 96,'97, to partially open or partially closed positions, the actuatingmechanism'shown and described in connection with FIG. 3 is operableinstead of the mechanism of FIG. 8. The same FIG. 3 mechanism can beinstalled with equal case on a frame such as the frame 93 to moveappropriate operating extensions which may be those attached to hookmembers or may be attached to any one of a variety of devices to whichthe mechanism can be advantageously applied.

While the invention has herein been shown and de scribed in whatconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of theinvention, which is not to be limited to the details disclosed hereinbut is to be accorded the full scope of the claims so as to embrace anyand all equivalent devices.

Having described the invention, what is claimed as new in support ofLetters Patent is:

1. In a portable device comprising a frame and a material handlingmechanism thereon having an operating arm the combination of a cableattached to the frame and to a stationary support for elevating andlowering said frame relative to the stationary support, a self-containedgas power actuator system on said frame for said operating armcomprising an operating cylinder, a double acting piston therein formingat opposite ends of the cylinder respectively a forward acting chamberand a reverse acting chamber, a gas supply under pressure therein, a gasline from the container, an operating valve device in the gas linedownstream from said receiver having a forward position connecting saidgas line with said forward acting chamber and exhausting said reversechamber to atmosphere and a reverse position connecting said gas line tosaid reverse chamber and exhausting said forward chamber to atmosphere,a valve actuator on said operating valve device movable respectively toforward and reverse positions, an operator in driving relationship withthe actuator including a trigger on the material handling mechanism at alocation engageable with said stationary support, said operator beingresponsive to pressure on the trigger when the frame is lowered towardthe stationary support whereby to effect a shifting of said operatingarm respectively to forward and reverse positions.

2. In a portable device comprising a frame a cable attached to the frameand to a stationary support, and a material handling mechanism on theframe having an operating arm, a self-contained gas power actuatorsystem for said operating arm mounted on the frame and comprising anoperating cylinder, a double acting piston therein forming at oppositeends of the cylinder respectively a forward acting chamber and a reverseacting chamber, a container on the frame having a gas supply underpressure therein above operating pressure, a gas line from thecontainer, a pressure reducing valve in the gas line, an operating valvedevice in the gas line having a forward position connecting said gasline with said forward acting chamber and exhausting said reversechamber to atmosphere and a reverse position connecting said gas line tosaid reverse chamber and exhausting said forward chamber to atmosphere,a valve actuator on said opera-ting valve device movable respectively toforward and reverse positions, an operator in driving relationship withthe actuator including a trigger on the material handling mechanism,said trigger having a position of operating engagement with saidstationary support when the cable acts to lower the mechanism to thestationary support, said operator being responsive to pressure of thestationary support thereon whereby to effect a shifting of saidoperating arm respectively to forward and reverse positions.

3. -In a portable device comprising a frame a cable attached to saidframe and to a stationary support, and a material handling mechanism onthe frame having an operating arm, the combination of a self-containedgas power actuator system for said operating arm mounted on the frameand comprising an operating cylinder, a double acting piston thereinforming at opposite ends of the cylinder respectively a forward actingchamber and a reverse acting chamber, a high pressure supply of gaseoussubstance comprising a container on the frame having a gas supply iniiquid condition, a gas line from the container, a pressure reducingvalve in the gas line, a gas receiver in said gas line downstream fromsaid reducing valve, an operating valve device in the gas linedownstream from said reducing valve having a forward position connectingsaid gas line with said forward acting chamber and exhausting saidreverse chamber to atmosphere and a reverse position connecting said gasline to said reverse chamber and exhausting said forward chamber toatmosphere, a valve actuator on said operating valve device movablealternately to forward and reverse positions, an operator in drivingrelationship with the actuator including a trigger on the materialhandling mechanism and a spring return therefor, said trigger having aposition of operating engagement with the stationary support when thecable acts to lower the mechanism in said support, said operator beingresponsive to pressure of the stationary support thereon against saidspring return whereby to effect a shifting of said operating armalternately to forward and reverse positions.

4. In a power actuated portable hook comprising a frame, a cable supporton said frame extending to a stationary support, a pair of pivotallymounted hook members on said frame cooperable with an external workelement on said stationary support and an operating extension on thehook members the combination of a self-contained gas power actuatorsystem for said operating extension comprising an operating cylinder, adouble acting piston in said cylinder separating said cylinder into anopening chamber and a closing chamber, a container for a high pressuresupply of gaseous substance, a gas line from the container, a four-wayoperating valve device in said gas line having an opening positionconnecting said gas line to the opening chamber and exhausting theclosing chamber to atmosphere and a closing position connecting said gasline to the closing chamber and exhausting the opening chamber toatmosphere, a valve actuator on the valve device movable alternately toopen and closed positions, an operator connected to the actuator andincluding a trigger movably mounted on the frame, said trigger having alocation engageable with said work element when the frame is lowered bythe cable to a position adjacent said support, said trigger beingresponsive to pressure exerted thereagainst by the external work elementwhen the frame is lowered to alternately effect opening and closing ofsaid hooks members.

5. In a power actuated portable hook comprising a frame, a cable supportattached to said frame and to a stationary support, a pair of pivotallymounted hook members on said frame cooperable with an external workelement on said support and an operating extension on the hook membersthe combination of a self-contained gas power actuator system for saidoperating extension comprising an operating cylinder, a double actingpiston in said cylinder separating said cylinder into an opening chamberand a closing chamber, a container for a high pressure supply of gaseoussubstance, a gas line from the container, a pressure reducing valve insaid gas line, an operating valve device in said gas line on thedownstream side of said reducing valve and having an opening posi-- tionconnecting said gas line to the opening chamber and exhausting theclosing chamber to atmosphere and a closing position connecting said gasline to the closing chamber and exhausting the opening chamber toatmosphere, a valve actuator on the valve device movable alternately toopen and closed positions, an operator connected to the actuatorincluding an automatic return and including a trigger movably mounted onthe frame at a location between said hook members, said trigger having aposition engageable with said work element when the frame is lowered bythe cable to a position adjacent said support, said trigger beingresponsive to pressure exerted thereagainst by the external work elementwhen the frame is lowered to alternately effect opening and closing ofsaid hook members.

References Cited in the file of this patent UNITED STATES PATENTS EysterApr. 19, 1898 l Gilli Sept. 23, 1941 ,1 Garlinghouse July 19, 1955 tGossett et'al Oct. 14, 1958 Weaver Oct. 14, 1958 Landry Aug. 9, 1960Schenk et a1. Dec. 6, 1960

3. IN A PORTABLE DEVICE COMPRISING A FRAME A CABLE ATTACHED TO SAIDFRAME AND TO A STATIONARY SUPPORT, AND A MATERIAL HANDLING MECHANISM ONTHE FRAME HAVING AN OPERATING ARM, THE COMBINATION OF A SELF-CONTAINEDGAS POWER ACTUATOR SYSTEM FOR SAID OPERATING ARM MOUNTED ON THE FRAMEAND COMPRISING AN OPERATING CYLINDER, A DOUBLE ACTING PISTON THEREINFORMING AT OPPOSITE ENDS OF THE CYLINDER RESPECTIVELY A FORWARD ACTINGCHAMBER AND A REVERSE ACTING CHAMBER, A HIGH PRESSURE SUPPLY OF GASEOUSSUBSTANCE COMPRISING A CONTAINER ON THE FRAME HAVING A GAS SUPPLY INLIQUID CONDITION, A GAS LINE FROM THE CONTAINER, A PRESSURE REDUCINGVALVE IN THE GAS LINE, A GAS RECEIVER IN SAID GAS LINE DOWNSTREAM FROMSAID REDUCING VALVE, AN OPERATING VALVE DEVICE IN THE GAS LINEDOWNSTREAM FROM SAID REDUCING VALVE HAVING A FORWARD POSITION CONNECTINGSAID GAS LINE WITH SAID FORWARD ACTING CHAMBER AND EXHAUSTING SAIDREVERSE CHAMBER TO ATMOSPHERE AND A REVERSE POSITION CONNECTING SAID GASLINE TO SAID